CD274 and triple-negative breast carcinoma: <h4>Aim</h4>To understand whether the worldwide implementation of PD-L1 testing in triple-negative breast cancer (TNBC) can be achieved in routine clinical practice.<h4>Methods and results</h4>The multicentre retrospective observational VANESSA study consecutively and uniformly enrolled patients treated with systemic therapy for early or metastatic (e/m)TNBC diagnosed between 2014 and 2017.